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Re: [CDT-L] GPS overkill?



Chet - 
Cool --- I wouldn't argue with you - but don't expect me to use one right
away either.  Just reading your explanation was more mental effort than
we used at any time on the CDT for navigation.  Different strokes.... 

Walk softly - in the right direction,
Jim


On Sat, 19 Feb 2000 20:35:35 -0500 Chet J Fromm <trailblazer@juno.com>
writes:
> It was stated here that a GPS is overkill, and more of a toy, not a
> serious insturment to use while hiking. I couldn't disagree more.
> Probably, someone said something like that when maps and compasses 
> were
> invented, "I know my stars and landmarks to navigate, I don't need 
> those
> new fangled land drawings and floating neddles." All methods and
> knowledge of navigation are useful, sometimes you must use all on 
> some
> type of hike, sometimes none. A GPS is an extention of navigation.
> 
> First of all when hiking, its best to use a GPS with a regular 
> compass
> (or electronic one) and a map(s). Unless you want to record a track 
> for
> future use (upload it to your computer later) its best to  turn it 
> on get
> your bearing, turn it off, and use a compass in between, turing on 
> the
> unit when you think it's necessary.
> 
> The main trick I've found is to preprogram waypoints before a hike. 
> This
> can be done using mapping apps, or there is a USGS site on the web, 
> that
> you enter a state and quad name, it returns many waypoints in that 
> quad.
> Use them as direct points or reference. You can get free state 
> published
> map catalog from the USGS, showing quad names, there are places on 
> the
> web to get freee topos.
> 
> With a compass and map, you must orient both to true or mag north, 
> to
> plot a direction from the map, or from a sighting. With a GPS you 
> must
> orient a map,but the unit will give you direction. The disavantage 
> is
> that you must be moving to get a direction from a GPS.
> 
> You have to use the map scale to plot a distance, a GPS will tell 
> you it.
> Both are "as the crow flies. If a mountain is between point A and B,
> neither is going to add the elevation gain and loss between, that's 
> what
> the contour lines (if you have them, many FS maps don't) tell you.
> 
> With a compass, to find the point your at now, you must at least 
> take at
> least two bearings to landmarks, match them to the map and bisect
> them.(Do that in a forest) With a GPS just turn it on, you got 
> location,
> match Lat\Long or UTM to the map.
> 
> Most compasses won't read to a accuracy of + or - 1degree. That 
> means in
> a mile, you could have 92 feet of lateral error. Coupled with 
> sometimes,
> mag declination is not stable, and/or as shown on a  map, average 
> for an
> area, you must use reference features to navigate. If you lose sight 
> of
> those, you have no means of determining if you drifted laterally or 
> not.
> 
> To check lateral drift  with a GPS, just turn it on, the CDI will 
> show
> you they way to move to the waypoint, even if you passed it and have 
> to
> backtrack, try doing that just with a compass and map! Usally, a GPS
> within a 100 or 300 ft of a point, a lot more accurate than a 
> compass,
> especially over long distances. As with compass navigation, 
> bracketing a
> point to reach using GPS is desirable(the waypoints on quads I 
> mentioned
> above)
> 
>  Just remember maps have errors on them (USGS quads claim accuracy 
> of a
> 100 feet). With a compass and map you still plot to that water 
> source.
> Preprogram the water waypoint in you GPS, it might not be there, 
> either
> way. A line with a pencil on a map might be .02 thick, thats 40 to 
> 100
> feet of ground distance error, depending on map scale!
> 
> To sum up, a GPS will also serve up ETA, ETA, UTC, moon & sun 
> phases,
> closer info, DOF, and many other features, much more than a compass.
> Worried about getting lost hurt(I get never lost, I'm just in a 
> different
> place than I was supposed to be)? Get a GPS cellphone, that way you 
> can
> tell someone, and give them directions to boot! Or get a Palm with 
> GPS,
> you also got all your other info stored.
> 
> I know some will still say the hell with a GPS, its to modern for 
> me, I
> got my compass skills. Well, which buried skier might be saved 
> first, one
> with a locator beacon, or without (modern gear)?  The route up Mt 
> Everest
> is known, but GPS and beacons are used there. Why are you using 
> modern
> boots, tent, backpack, sleep bag, instead of leaves on da foots, 
> building
> shelter on a trail, wiker basket pack, a plain blanket? One word,
> Convenience! Same same GPS.
>  _________________________________
>   []0  AT 87-88                    
>   []|- FT 89                                       
>   []|  PCT 90-91                  
>    /^\ NCT 92-95                  
>   /__ \_  Backpacker Guide        
>  www.geocities.com/Yosemite/1140 
> _trailblazer@juno.com______                                          
>     
>                          
> 
> 
> 
> 
> 
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